The present invention encompasses articles designed to deliver a pre-determined amount of a bleaching composition. More specifically, articles comprising starch-thickened peroxygen bleaches releasably contained in a receptacle are distributed evenly over fabrics by the tumbling action of an automatic clothes dryer. The articles can also be used to deliver a pre-measured amount of bleach to a laundry bath.
Compositions and processes designed to provide desirable functional and aesthetic benefits to fabrics are conventionally employed in a washing machine. Thus, fabric sizings, softening agents, bleaches, brighteners, and the like, are commonly formulated and provided as compositions designed for use either in an aqueous laundering liquor or in an aqueous rinse bath. More recently, the treatment of fabrics in automatic clothes dryers has been shown to be an effective means for imparting desirable properties thereto. For example, it is becoming common to soften fabrics in an automatic clothes dryer rather than during the rinse cycle of a laundering operation. In either mode of treating fabrics it is convenient to provide the user with a pre-determined amount of the fabric treating agent so that measuring and under-usage are avoided.
By the present invention, a pre-measured amount of a bleaching composition comprising a highly effective peroxygen bleach incorporated into a starch-thickened carrier is placed in a dispensing means to provide a bleaching article. The article is used to bleach fabrics in an aqueous laundry bath at alkaline pH's (e.g., in the presence of standard detergents or pre-soaks which provide a pH in the alkaline range), or in a clothes dryer at elevated temperatures. The starch-thickened bleaches herein are exceptionally stable from the standpoint of both peroxygen bleach stability and stability of the overall, thickened compositions. Accordingly, the present articles are characterized by their exceptionally good shelf-life. Most importantly from the standpoint of a dryer-added bleaching product, the starch-thickened bleaches herein do not cause substantial visible damage to fabric dyes.
The concurrently-filed applications of Diehl, et al., and Marsan, et al., Ser. Nos. 562,527 and 562,529, relate to dryer-added bleaching articles containing thickened bleaches.
The concurrently-filed application of Bradley, Ser. No. 562,531, relates to a starch-thickened bleach for use in an aqueous laundry bath.
The concurrently-filed application of Edwards, et al., Ser. No. 562,530, relates to non-starch thickened bleaches used in laundry baths.
U.S. Pat. No. 3,701,202 describes a dispensing article for use in an automatic clothes dryer and suggests that fabrics may be softened, bleached and otherwise desirably treated in the dryer by means of such an article. See also, U.S. Pat. No. 3,180,037.
The co-pending application of Diehl and Edwards, Ser. No. 437,569, filed Jan. 29, 1974, discloses certain solid, dryer-added peroxygen bleaches which provide substantial bleaching superiority over dry bleaching compositions employed in a laundering liquor.
The co-pending application of Lucas, McKenna and Diehl, Ser. No. 437,570, filed Jan. 29, 1974, discloses bleaching articles comprising a porous pouch containing a solid, activated bleach.
U.S. Pat. No. 3,843,548, entitled COMPOSITIONS CONTAINING A SOURCE OF HYPOCHLORITE IONS, to R. James, issued Oct. 22, 1974, discloses clay-thickened hypochlorite bleaches. Hydrogen peroxide bleaches thickened with silica gel are known in the hair bleaching art. German Pat. No. 2,408,636, published Sept. 5, 1974, U.S. application Ser. No. 335,311, Feb. 23, 1973, relates to the use of fabric treating agents other than bleaches encapsulated with various organic gelling agents and used, in solid form, in a clothes dryer.
The following references generally relate to peroxygen compounds and their use as oxidizing agents and/or bleaches: Canadian Pat. No. 635,620 to H. W. McCune, issued Jan. 30, 1962; British Pat. No. 847,702, issued Sept. 14, 1960; W. E. Parker, et al., J. Am. Chem. Soc., 79, 1929 (1957); E. Searles, "Preparation, Properties, Reactions and Use of Organic Peracids and their Salts," FMC Corp., N.Y. (1964); D. Swern (ed.) "Organic Peroxides", Vol. I, Wiley-Interscience, N.Y. (1970).
It is an object of this invention to provide a means for dispensing fabric bleaches in an even and efficient manner without recourse to complicated dispensers or machine modifications.
It is another object to provide color-safe, yet effective, fabric bleaches in releasable combination with a simple, economical dispensing means.
These and other objects are obtained herein as will be seen from the following disclosure.